Knife gate valve

Abstract

A valve for controlling the flow of materials is provided. The valve has a valve body having a bore, a guide attached to the valve body, a gate movable within the guide into and out of the bore, and an actuator for the gate, the bore of the valve body having a profile where the gate enters the bore, and the gate having a concave leading edge conforming to a profile of the bore. The valve may be used in throttling applications.

1. A valve comprising:
 a valve body having a bore; 
 a guide attached to the valve body; 
 a gate movable within the guide into the bore from a retracted position and out of the bore into the retracted position; 
 an actuator for the gate; 
 the bore of the valve body having sides and a bore width between the sides, and the bore having a profile where the gate enters the bore; 
 the gate having a concave leading edge conforming to the profile of the bore, the concave leading edge of the gate being flush with the profile of the bore where the gate enters the bore to eliminate exposed chest area when the gate is in the retracted position; and 
 the gate having a gate width less then the bore width to produce gaps between the sides of the bore and the gate when the gate is extended into the bore. 
 
   
   
     2. The valve of  claim 1 , where the gate is a knife gate. 
   
   
     3. The valve of  claim 1  where the valve body further comprises retainer rings and a valve body bore liner. 
   
   
     4. The valve of  claim 3  where the retainer rings and valve body bore liner are replaceable. 
   
   
     5. The valve of  claim 1 , where the valve body further comprises an insert, the insert creating an obstruction in the bore. 
   
   
     6. The valve of  claim 5 , where the insert is V-shaped. 
   
   
     7. The valve of  claim 1  in which:
 the bore is circular and has a radius; 
 the knife gate has parallel sides separated by the gate width; 
 the gate width is less than the radius of the bore; and 
 the leading edge of the gate has a leading edge radius equal to the radius of the bore. 
 
   
   
     8. A knife gate valve comprising:
 a valve body having a bore; 
 a guide attached to the valve body; 
 a gate movable within the guide into the bore from a retracted position and out of the bore into the retracted position; 
 an actuator for the gate; 
 the bore of the valve body having sides and a bore width between the sides, and the bore having a profile where the gate enters the bore; 
 the gate having a recessed leading edge conforming to the profile of the bore, the recessed leading edge of the gate being flush with the profile of the bore where the gate enters the bore to eliminate exposed chest area when the gate is in the retracted position; and 
 the gate having a gate width less then the bore width to produce gaps between the sides of the bore and the gate when the gate is extended into the bore. 
 
   
   
     9. The knife gate valve of  claim 8  in which:
 the bore is circular and has a radius; 
 the knife gate has parallel sides separated by the gate width; 
 the gate width is less than the radius of the bore; and 
 the leading edge of the gate has a leading edge radius equal to the radius of the bore.